particles suck

src/main/java/at/petrak/hexcasting/common/casting/OperatorSideEffect.kt

@@ -2,13 +2,19 @@ package at.petrak.hexcasting.common.casting
 
 import at.petrak.hexcasting.api.RenderedSpell
 import at.petrak.hexcasting.api.SpellDatum
+import at.petrak.hexcasting.common.particles.HexParticles
 import at.petrak.hexcasting.datagen.Advancements
+import com.mojang.math.Quaternion
 import com.mojang.math.Vector3f
 import net.minecraft.Util
-import net.minecraft.core.particles.DustParticleOptions
 import net.minecraft.network.chat.TextComponent
 import net.minecraft.network.chat.TranslatableComponent
+import net.minecraft.util.Mth
 import net.minecraft.world.phys.Vec3
+import kotlin.math.acos
+import kotlin.math.cos
+import kotlin.math.sin
+import kotlin.math.sqrt
 import kotlin.random.Random
 import kotlin.random.nextInt
 
@@ -50,7 +56,8 @@ sealed class OperatorSideEffect {
         }
     }
 
-    data class Particles(val position: Vec3) : OperatorSideEffect() {
+    data class Particles(val position: Vec3, val velocity: Vec3, val fuzziness: Double, val spread: Double) :
+        OperatorSideEffect() {
         override fun performEffect(harness: CastingHarness): Boolean {
             val colorizer = harness.getColorizer()
 
@@ -58,16 +65,32 @@ sealed class OperatorSideEffect {
                 // For the colors, pick any random time to get a mix of colors
                 val color = colorizer.getColor(Random.nextFloat() * 256f, Vec3.ZERO)
 
-                harness.ctx.world.sendParticles(
-                    DustParticleOptions(Vector3f(Vec3.fromRGB24(color)), 1f),
-                    position.x,
-                    position.y,
-                    position.z,
-                    1,
-                    0.1,
-                    0.1,
-                    0.1,
-                    0.1,
+                // https://math.stackexchange.com/questions/44689/how-to-find-a-random-axis-or-unit-vector-in-3d
+                fun randomInCircle(maxTh: Double = Mth.TWO_PI.toDouble()): Vec3 {
+                    val th = Random.nextDouble(0.0, maxTh)
+                    val z = Random.nextDouble(-1.0, 1.0)
+                    return Vec3(sqrt(1.0 - z * z) * cos(th), sqrt(1.0 - z * z) * sin(th), z)
+                }
+
+                val offset = randomInCircle().scale(fuzziness)
+                val pos = position.add(offset)
+
+                // https://math.stackexchange.com/questions/56784/generate-a-random-direction-within-a-cone
+                val northCone = randomInCircle(spread)
+                val velNorm = velocity.normalize()
+                val zp = Vec3(0.0, 0.0, 1.0)
+                val rotAxis = velNorm.cross(zp)
+                val th = acos(velNorm.dot(zp))
+                val dagn = Quaternion(Vector3f(rotAxis), th.toFloat(), false)
+                val velf = Vector3f(northCone)
+                velf.transform(dagn)
+                val vel = Vec3(velf).scale(velocity.length())
+
+                // TODO: this doesn't work because xyz velocity is a lie
+                harness.ctx.world.addParticle(
+                    HexParticles.CONJURE_BLOCK_PARTICLE.get(),
+                    pos.x, pos.y, pos.z,
+                    vel.x, vel.y, vel.z,
                 )
             }
 

src/main/resources/assets/hexcasting/particles/conjure_light_particle.json

@@ -1,11 +1,5 @@
 {
-	"textures": [
-		"hexcasting:spin_cube_7",
-		"hexcasting:spin_cube_6",
-		"hexcasting:spin_cube_5",
-		"hexcasting:spin_cube_4",
-		"hexcasting:spin_cube_3",
-		"hexcasting:spin_cube_2",
-		"hexcasting:spin_cube_1"
-	]
+  "textures": [
+    "hexcasting:cloud"
+  ]
 }